China
Africa
Explore chapters and articles related to this topic
Power Distribution Equipment
Published in Dale R. Patrick, Stephen W. Fardo, Brian W. Fardo, Electrical Power Systems Technology, 2021
Dale R. Patrick, Stephen W. Fardo, Brian W. Fardo
Thermal overload relays are often used as protective devices. Thermal relays may be reset either manually or automatically. One type of thermal overload relay uses a bimetallic heater element. The bimetallic element bends as it is heated by the current flowing through it. When the current reaches the rating of the element, the relay opens the branch circuit. Another type of element is the melting alloy type. This device has contacts held closed by a ratchet wheel. At the current capacity of the device, the fusible alloy melts, causing the ratchet wheel to turn. A spring then causes the device to open the circuit.
Power Distribution Equipment
Published in Stephen W. Fardo, Dale R. Patrick, Electrical Power Systems Technology, 2020
Stephen W. Fardo, Dale R. Patrick
Thermal overload relays are often used as protective devices. Thermal relays may be reset either manually or automatically. One type of thermal overload relay uses a bimetallic heater element. The bimetallic element bends as it is heated by the current flowing through it. When the current reaches the rating of the element, the relay opens the branch circuit. Another type of element is the melting alloy type. This device has contacts held closed by a ratchet wheel. At the current capacity of the device, the fusible alloy melts, causing the ratchet wheel to turn. A spring then causes the device to open the circuit.
Fire Protection and Prevention
Published in W. David Yates, Safety Professional’s Reference and Study Guide, 2020
There are several categories of sprinkler systems that may include dry pipe, wet pipe, deluge, combined dry pipe and pre-action, and sprinklers that are designed for limited water supply systems. A fire sprinkler system consists of a water supply that provides adequate pressure and flow rate to a water distribution piping system, which has sprinkler heads attached. The sprinkler heads are held closed by either a heat-sensitive glass bulb or a two-part metal link held together with fusible alloy. The sprinkler heads have varying degrees of temperature sensitivities and are color-coded. These color codes are identified in Table 10.3.
Zero CO2 steelmaking in a future low carbon economy. 2. Secondary steelmaking using refined iron slab, with clean and contaminated scrap
Published in Mineral Processing and Extractive Metallurgy, 2018
The estimated electrical power requirement to produce one tonne slab steel product from steel scrap and refined primary iron slab is potentially less than 175 kWh, using the proposed new technology employing a liquid metal coolant in continuous casting. Low alloy ferritic steel can be used in the construction of plant handling molten lead–bismuth eutectic at temperatures up to around 550°C, which encompasses the majority of the heat recovery system. Electrical conductive heating can be used throughout in the transportation of the fusible alloy coolant and submerged centrifugal pumps are commercially well proven in similar extractive metallurgy plant configurations.